Fred Lowe Soper was born December 13, 1893 in Hutchinson, Kansas, the third of Socrates and Mary Ann Soper's eight children. His father was a pharmacist and his mother a schoolteacher. "From the beginning, it was assumed that each of the Soper children would attend the local high school and from there go to the state university," Soper recalled in his memoirs, and seven of the eight did so. Several of his brothers became physicians, as did Fred. Likewise, all the Soper siblings were expected to work and save money toward their education. Soper later commented that one part-time job, selling stereoscopic viewers and slides door-to-door, developed the skills he would use to "sell" health programs during his public health career.

Soper earned a B.A. (1914) and a M.S. in Embryology (1916) from the University of Kansas, acquiring much practical laboratory experience in the process. He continued on to Rush Medical College at the University of Chicago, where he received his M.D. in 1918. During his last year at Rush, he was recruited by the Rockefeller Foundation's International Health Board. Although he had no specific interest in public health work at the time, the Rockefeller's $200 monthly salary was attractive in the uncertain economy after the First World War. After a year's internship at Chicago's Cook County Hospital, Soper started work at the Rockefeller Foundation in January 1920. After a 3-week course in parasitology, at Johns Hopkins University, Soper and his new wife--he had married Juliet Snider on December 27, 1919--sailed for Brazil to begin his first assignment.

During 1920 and 1921, Soper worked in northeastern Brazil, conducting hookworm surveys and organizing hookworm campaigns in the states of Pernambuco and Alagoas, working with local and state public health staff. Late in 1921, he was transferred to Rio Grande do Sul in southern Brazil to oversee hookworm programs already in place. He returned to the U.S. for the 1922-23 academic year to earn a Certificate (Master) in Public Health at Johns Hopkins School of Hygiene and Public Health. Afterward he spent four months in public health field training in Alabama and Georgia before returning to South America. From late 1923 to mid-1927, Soper administered hookworm control programs in Paraguay and systematically tested the efficacy of the several available hookworm remedies.

By the late 1920s, the Rockefeller Foundation was phasing out its hookworm disease programs; Soper was reassigned to Rio de Janeiro in 1927, as administrative head of Rockefeller's regional office. In this post he helped conceive and carry out effective campaigns against yellow fever and malaria. He demonstrated that, with proper techniques and meticulous organization, the mosquito vectors of these diseases could be virtually eradicated. He incorporated laboratory analysis into the post-mortem diagnosis of yellow fever--through characteristic changes in liver tissue--and then was able to identify cases of "jungle yellow fever" that occurred even without the Aedes aegypti mosquito, its usual vector. In 1946, Soper was presented with one of the first Lasker Awards "for his splendid organization of eradication campaigns against yellow fever and malaria which have set new standards in the fight to defeat these diseases." He remained a staunch advocate of disease eradication programs ever after.

With Brazil's malaria threat largely eliminated, and World War II underway, Soper left Brazil in September of 1942. On loan from the Rockefeller Foundation, he became an infectious disease consultant to the U.S. Secretary of War. In this capacity he joined the U.S. Typhus Commission, which had been formed to address the outbreaks of louse-borne typhus fever among civilians and military in North Africa and the Middle East. Between 1943 and 1946, Soper, with personnel from the Rockefeller Foundation and the Allied military health services conducted de-lousing operations in Egypt, Algeria, and Naples, Italy. In the process, they developed an efficient, effective, low-cost typhus control protocol using insecticide powders, including the then-new DDT. From 1944 to 1946, Soper also worked on malaria control programs in Egypt and Italy.

The Rockefeller Foundation made Soper Regional Director for Africa and the Middle East in 1946, but in 1947 he was elected Director of the Pan American Sanitary Bureau (PASB), the executive agency of the Pan American Sanitary Organization, a post he would occupy until 1959. Under his direction, PASB increased its budget (from $115,000 to over $10 million per year) and its staff (from 88 to 750) and greatly expanded its health programs throughout the Americas. Importantly, Soper also negotiated on PASB's behalf with the nascent World Health Organization (WHO), persuading the other WHO delegates to make PASB the Regional Office for the Americas of WHO. Between 1949 and 1959, PASB programs helped clear many areas of South and Central America of diseases such as yaws and malaria and worked on smallpox eradication.

Soper retired from PASO (renamed Pan American Health Organization in 1958) in 1959, becoming Emeritus Director. He continued to be active in the international health community, however, serving as a malaria eradication consultant for the International Cooperation Administration's Agency for International Development, and directing the Pakistan-Southeast Asia Treaty Organization (SEATO) Cholera Research Laboratory in Bangladesh (1960-1962). From 1962 to 1972 he was a Special Consultant to the Office of International Health at the U.S. Public Health Service. From 1949 to 1966, he was also a Visiting Lecturer on Tropical Public Health at the Harvard University School of Public Health.

During his career, Soper was author or co-author of some 124 scientific papers and two classic books, Anopheles Gambiae in Brazil, 1930 to 1940 (1943) and The Organization of Permanent Nation-Wide Anti-Aedes Aegypti Measures in Brazil (1943), and gave many presentations. His final publication was his memoirs, titled Ventures in World Health, published in 1977 shortly after his death.

In the international public health community, Fred Soper stands out as one of the most successful practitioners of preventive medicine and public health in the middle fifty years of the twentieth century. Paul F. Russell, a Rockefeller colleague and lifelong friend, noted that Soper was endowed with optimism and vision, an extraordinary ability to select and inspire capable, loyal staffs, an exceptional talent for organizing and administering difficult projects, and skill in selecting and improving effective tools. Others have pointed to his personal and intellectual integrity, his sensitivity to the milieux in which he worked, and his fearless tenacity in dealing with superiors and government officials.

His work was recognized by many honors, including the Lasker Award (1946), Theobald Smith Gold Medal (1949), Pan American Health Organization Gold Medal (1959), American Public Health Association Sedgwick Medal (1966), World Health Organization Leon Bernard Foundation Prize (1967), and the American Society of Tropical Medicine and Hygiene Walter Reed Medal (1972), along with awards from many South American organizations.